Deprecated arithmetic between enumeration and floating point types

[stephenswat]

Dear detray developers, while trying to compile traccc with C++20 enabled I encountered an issue stemming from detray, namely that deprecated arithmetic between enumeration and floating point types is used here:

detray/core/include/detray/propagator/constrained_step.hpp

Line 81 in 36f9fcd

return dir * min();

Please consider adding static casts to turn this enumeration type into a floating point type, or use a conditional to multiply without relying on implicit conversion.

[niermann999]

This is related to #337 and will need to be rewritten at some point. Unsigned integer to floating point conversions will be cleaned out in #372 . But for this particular issue, see #375 for a quick fix